Files in this package

Content in the Dryad
Digital Repository is offered "as is." By downloading files, you agree
to the Dryad Terms of Service.
To the extent possible under law, the authors have waived all copyright
and related or neighboring rights to this data.

Title

Seasonal resighting histories of adult Eurasian spoonbills

Downloaded

61 times

Description

The datafile contains seasonal resighting histories of 538 adult Eurasian spoonbills that breed in the Netherlands or Germany and winter in France, Iberia or Mauritania, resighted between October 2005 and September 2012. Resighting periods are defined as October-December and January-March in an individual's wintering area and April-June and July-September in the breeding areas in The Netherlands and Germany. The resighting history of an individual starts with the first resighting as an adult (3rd winter or older) in its wintering region, being France, Iberia or Mauritania (and indicated in the column "group" of the datafile). Further details can be found in the Supplementary Material associated with the manuscript.

AbstractExplanations for the wide variety of seasonal migration patterns of animals all carry the assumption that migration is costly and that this cost increases with migration distance. Although in some studies, the relationships between migration distance and breeding success or annual survival are established, none has investigated whether mortality during the actual migration increases with migration distance. Here, we compared seasonal survival between Eurasian spoonbills (Platalea leucorodia leucorodia) that breed in The Netherlands and migrate different distances (ca 1000, 2000 and 4500 km) to winter in France, Iberia and Mauritania, respectively. On the basis of resightings of individually marked birds throughout the year between 2005 and 2012, we show that summer, autumn and winter survival were very high and independent of migration distance, whereas mortality during spring migration was much higher (18%) for the birds that wintered in Mauritania, compared with those flying only as far as France (5%) or Iberia (6%). As such, this study is the first to show empirical evidence for increased mortality during some long migrations, likely driven by the presence of a physical barrier (the Sahara desert) in combination with suboptimal fuelling and unfavourable weather conditions en route.